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Don't know your RBI from your ERA? Not sure what hitting a sacrifice fly or making a triple play involves?

Baseball is a simple game complicated by jargon, so here is BBC Sport Interactive's guide to the key terms that might cause confusion.

THE MAJOR LEAGUES

The Majors are two leagues - American and National - each has three divisions: West, Central and East.

Every team plays every other in their league, and they play more games against those in their division. The leagues don't meet until the World Series, apart from a few specially created interleague games.

The leagues also play an All-Star exhibition game during the mid-season break, with the starting outfield players selected by a fans' ballot.

Each team plays 162 regular season games. They play each other in three or four-game series, and teams often play a string of these away on a road trip.

Each league's three divisional winners are joined by one wild card to make up the league semi-finals, followed by best-of-seven league finals and then the World Series, also known as the Fall Classic.

KEY TERMS - BATTING

AT BATS (AB): Turns at batting. Normally four or five per game for a starting outfield player.

HITS (H): Any time a player connects with the ball and gets to at least first base. This is the most important statistic for a non-pitcher.

You don't get a hit if a fielder makes a mistake, known as an error , or decides to throw to another base to get somebody else out, a fielder's choice.

Getting to first is called a single, second a double, third a triple (quite rare), and all the way around is a home run. But they all count as one hit.

A batter who records the rare feat of a single, a double, a triple and a home run in the same game is said to have hit for the cycle.

BATTING AVERAGE (AVG): As in cricket, this is the key measure of player's worth. In short, this is hits divided by at bats.

Florida Marlins lead-off hitter Juan Pierre

The average is calculated as a fraction of one, ie. 0.300 (the benchmark of a good player) means the batter gets a hit in 30% of his at bats. Hence, you may see references to a player's average being .300.

Batting averages do not include getting on base via a walk - when the pitcher throws four pitches, or balls outside the strike zone.

Also not counted are sacrifice flies (when a batter hits the ball far enough for a player to score after the catch has been made), being hit by the pitch (which gives you first base), and fielder's choices or errors.

A good batting average is anything over .300; a decent one is about .260; anything below .240 is poor.

Pitchers bat only in the National League (the American League uses designated hitters, who do not field, in their place), and like bowlers in cricket they tend to bat at the end of the nine-man order.

Towards the end of a close game they, and other bad batters, are often substituted so that pinch hitters can take their at bat.

ON BASE PERCENTAGE (OBP): Like the above but includes all those other bits too. A good OBP is .400 - anything below .300 is bad.

STOLEN BASE (SB): Once on base, fast-running players will try to steal a base - normally from first to second, as second base is the furthest throw for the catcher to make from behind home plate.

Stealing a base adds a sudden burst of drama to a game

The player on base starts running as soon as the pitcher begins his action. If the pitcher attempts to break his action by throwing to base instead of the plate it is called a balk, which advances players on base.

The player attempts to beat the catcher's throw to the second baseman or shortstop (the two fielders who defend the middle of the infield).

SBs are important because if a player gets to second base he can normally get home for a run on a base hit.

A pitcher can try to stop people stealing bases by keeping them close to first base.

The runner will try to get a good head start by going as far from first base as he dares.

But if a pitcher can throw the ball to the first baseman before the runner gets back to the bag, the fielder can tag him out. This is called a pick off.

RUNS BATTED IN (RBI): After batting averages, this is the most important batting stat. You get an RBI every time you enable someone to score (including yourself).

So, if you hit a home run you get one because you have scored. If you get hit by the pitch when the bases are loaded (players on first, second and third), you get an RBI as everyone has to move around one base. If you hit a home run with the bases loaded (a grand slam) you get four RBIs.

KEY TERMS - PITCHING & FIELDING

EARNED RUN AVERAGE (ERA): After their win-loss record, this is the key stat for pitchers (akin to bowling averages in cricket).

An ERA is how many runs a pitcher gives up per nine innings. Runs scored by players who got on base due to an error are not his fault and therefore unearned - a bit like byes on a bowling average.

A good ERA is anything below 4.00 (ie four runs per nine innings), a bad one is 6.00+.

SAVES (SV): Not every pitcher is a starter - most teams have a rotation of 4-5 starters. The rest of the pitching staff or bullpen (usually 10-12 players) are known as relievers.

Relief pitcher Ugueth Urbina in action for Florida

When the starting pitcher gets tired or is having an off day, a team manager calls in a reliever.

If the team was still leading when the starter retired, you are attempting to complete the win and earn a save.

A pitcher only earns a save if the lead he inherits is three runs or less, and he has to pitch at least a full inning.

The best relievers, known as closers, will normally only pitch the last innings. They are often preceded by set-up men who tend to pitch the eighth innings. Relievers that bail out starters earlier in the game by pitching for two or more innings are called middle relievers.

If a reliever enters the game in a save situation and lets the opposition win, that is a blown save.

A starter going all the way to the end pitches a complete game. If he does this without giving up a hit that is a no-hitter, which is very rare. Even rarer is a perfect game - no hits or walks, just 27 straight outs.

STRIKEOUTS: Three strikes and you're out. The only complicating factor is foul balls. If the batter hits the ball behind the tramlines that extend into the stands from the lines marking first and third base this is called a foul.

This counts as a strike against the batter, but only up to two strikes. The only way you can foul out is by fouling a bunt - the baseball equivalent of a drop shot in tennis - attempt on two strikes. This is very rare.

Balls are pitches outside the strike zone (over the plate between the batter's knees and chest) - four of those and you get a walk.

A hit batsman speaks for itself - the result is the same as a walk.

A wild pitch is when the pitcher misses his target making it impossible for the catcher to do his primary job.

If he misses a catch he should have held, allowing a runner or runners to advance, this is known as a passed ball (PB).

DOUBLE PLAY (DP): In a bases loaded situation, if you're on first and the batter hits the ball, you have to start running.

If the ball fails to get past the infield (the innermost four fielders) there is a good chance that they can get the man on base out and still have time to throw to first to get you out.

A triple play is very rare, and rarer still is an unassisted triple play where a fielder makes all three outs himself - usually, by catching a line drive, stepping on a base to get one runner out, and tagging another runner with the ball between bases.

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